from transformers import pipeline, AutoTokenizer, VisionEncoderDecoderModel, AutoProcessor, Qwen2VLForConditionalGeneration
from PIL import Image
from io import BytesIO
import base64
import json
import torch
from qwen_vl_utils import process_vision_info
import prompt

# Chuyển ảnh thành base64 (tùy chọn nếu bạn cần hiển thị hoặc xuất)
def pil_to_base64(image: Image.Image, format="PNG") -> str:
    buffered = BytesIO()
    image.save(buffered, format=format)
    buffered.seek(0)
    return base64.b64encode(buffered.read()).decode("utf-8")

def parse_to_json(result_text):
    """
    Nếu output là các dòng 'key: value', parse thành dict.
    Nếu không, gói nguyên text vào trường 'text'.
    """
    data = {}
    lines = [line.strip() for line in result_text.splitlines() if line.strip()]
    for line in lines:
        if ":" in line:
            key, val = line.split(":", 1)
            data[key.strip()] = val.strip()
        else:
            # Nếu không tách được, gom vào list chung
            data.setdefault("text", []).append(line)
    # Nếu chỉ có list 'text', chuyển về chuỗi
    if set(data.keys()) == {"text"}:
        data = {"text": "\n".join(data["text"])}
    return data

# class TrOCRModel:
#     def __init__(self, model_id="microsoft/trocr-base-printed", cache_dir=None, device=None):
#         self.model_id = model_id
#         self.cache_dir = cache_dir
#         self.device = device

#         self.processor = TrOCRProcessor.from_pretrained(self.model_id, cache_dir=self.cache_dir)
#         self.model = VisionEncoderDecoderModel.from_pretrained(self.model_id, cache_dir=self.cache_dir)
#         self.model.to(self.device)

#     def predict(self, image: Image.Image) -> str:
#         if image is None:
#             raise ValueError("No image provided")

#         image = image.convert("RGB")
#         pixel_values = self.processor(images=image, return_tensors="pt").pixel_values.to(self.device)

#         with torch.no_grad():
#             generated_ids = self.model.generate(pixel_values)
#             generated_text = self.processor.batch_decode(generated_ids, skip_special_tokens=True)[0]

#         return generated_text

class TrOCRModel:
    def __init__(self, model_id="microsoft/trocr-base-printed", cache_dir=None, device=None):
        self.pipe = pipeline("image-to-text", model=model_id, device=device)

    def predict(self, image: Image.Image) -> str:
        if image is None:
            raise ValueError("No image provided")

        image = image.convert("RGB")
        result = self.pipe(image)
        return result[0]['generated_text'] if result else ""
    
class EraXModel:
    def __init__(self, model_id="erax-ai/EraX-VL-2B-V1.5", cache_dir=None, device="auto"):
        size = {
            "shortest_edge": 56 * 56,   # đủ chi tiết, dùng phổ biến trong ViT/TrOCR
            "longest_edge": 1280 * 28 * 28    # giới hạn chiều dài ảnh nếu là ảnh dọc hoặc ngang dài
        }

        # with open(config_json_path, 'r', encoding='utf-8') as f:
        #     self.json_template = json.dumps(json.load(f), ensure_ascii=False)

        self.model = Qwen2VLForConditionalGeneration.from_pretrained(
            model_id,
            cache_dir=cache_dir,
            torch_dtype=torch.bfloat16,
            attn_implementation="eager", # replace with "flash_attention_2" if your GPU is Ampere architecture
            device_map="auto",
        )
        self.tokenizer =  AutoTokenizer.from_pretrained(model_id, cache_dir=cache_dir)
        self.processor = AutoProcessor.from_pretrained(
            model_id,
            size=size,
            cache_dir=cache_dir,
        )

        # Generation configs
        self.generation_config =  self.model.generation_config
        self.generation_config.do_sample   = True
        self.generation_config.temperature = 1.0
        self.generation_config.top_k       = 1
        self.generation_config.top_p       = 0.9
        self.generation_config.min_p       = 0.1
        self.generation_config.best_of     = 5
        self.generation_config.max_new_tokens     = 784
        self.generation_config.repetition_penalty = 1.06

    def predict(self, image: Image.Image) -> str:
        if image is None:
            raise ValueError("No image provided")
        
        # image_path = "image.png"
        # # Read and encode the image
        # with open(image_path, "rb") as f:
        #     encoded_image = base64.b64encode(f.read())
        # decoded_image_text = encoded_image.decode('utf-8')
        # base64_data = f"data:image;base64,{decoded_image_text}"
        
        decoded_image_text = pil_to_base64(image)
        base64_data = f"data:image;base64,{decoded_image_text}"

        # Prepare messages
        messages = [
            {
                "role": "user",
                "content": [
                    {
                        "type": "image",
                        "image": base64_data,
                    },
                    {
                        "type": "text",
                        "text": prompt.CCCD_BOTH_SIDE_PROMPT,
                    },
                ],
            }
        ]

        # Prepare prompt
        tokenized_text = self.processor.apply_chat_template(
            messages, tokenize=False, add_generation_prompt=True
        )
        print("Tokenized text")
        image_inputs, video_inputs = process_vision_info(messages)
        print("Processed vision info done")

        inputs = self.processor(
            text=[tokenized_text],
            # images=image_inputs,
            images=[image],
            # videos=video_inputs,
            padding=True,
            return_tensors="pt",
        ).to(self.model.device)
        print("Inputs prepared")

        # Inference
        print("Generating text...")
        generated_ids = self.model.generate(**inputs, generation_config=self.generation_config)
        generated_ids_trimmed = [
            out_ids[len(in_ids) :] for in_ids, out_ids in zip(inputs.input_ids, generated_ids)
        ]
        output_text = self.processor.batch_decode(
            generated_ids_trimmed, skip_special_tokens=True, clean_up_tokenization_spaces=False
        )

        return output_text[0]